KLK3 and posterior cortical atrophy: Heterogeneous and discordant AR and PSA expression in PCa cells has been reported in numerous earlier studies [39–61]; however, our study, for the first time, has proposed and presented the evidence for the 4 subtypes of PCa cells, i.e., AR+PSA+, AR−PSA+, AR+PSA−, and AR−PSA+ that pre-exist in untreated HPCa.